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Study of the production of lignolytic enzymes by white rot fungi
Vejdová, Markéta ; Bendová, Agáta (referee) ; Hudečková, Helena (advisor)
The topic of this bachelor thesis is the study of ligninolytic enzyme production by white rot fungi. The theoretical part of the thesis is focused on the characterization of wood-decay fungi, especially white rot fungi, and the ligninolytic enzymes produced on the synthetic and waste substrates for cultivation of the fungi and the impact of pH on the biomass growth. The experimental part focuses on the submerged cultivation of selected fungal strains Trametes versicolor CCBAS 1383 and Irpex lacteus CCBAS 196 at different pH levels. Samples were taken over a period of 36 days to observe the activities of individual ligninolytic enzymes, the content of total extracellular proteins, and biomass growth. The same parameters were also observed during the submerged cultivation of Trametes versicolor CCBAS 1383 on waste substrate. Based on the comparison of the results of selected fungal strains, it can be stated that the optimization of the cultivation medium, particularly the pH level, has a significant impact on the activity of produced enzymes. The highest enzyme activities were achieved by the submerged cultivation of Trametes versicolor at pH 5. An exception is lignin peroxidase, which reached a maximum activity of only (4 ± 1) · 10 U at this pH, while the highest activity of lignin peroxidase (1,2 ± 0,4) · 10 U was measured at pH 7. Overall, Trametes versicolor is a more suitable producer of ligninolytic enzymes compared to Irpex lacteus.
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Biodegradace azobarviv působením hub bílé hniloby
Bírošíková, Paulína
White rot fungi, belonging to wood decay fungi have the ability to degra-de complex aromatic structures such as lignin or pollutants with an aromatic structure (tetracyclines, endocrine disruptors) via extracellular ligninolytic enzymes. Azo dyes are synthetic dyes containing aromatic rings with bonded substituents lin-ked by an azo group. Fungi are able to degrade these structures, whereas decrease of dye is observed, called decolorization. The aim of this bachelor's thesis is to de-termine the degradation ability of three types of azo dyes (methylene red, tartrazine and azorubin) using ten types of white rot fungi. Cultivation of individual fungi with the dyes was carried out for twenty-four days, during which the absorbance was monitored using a UV/VIS spectrophotometer at intervals of every other working day. The colour loss was calculated from the measured values and the decoloriza-tion values were expressed graphically as a percentages. The selected fungi showed the greatest decolorization of tartrazine on the second day of the experiment, an average of 89%, except for the fungus Fomes fomentarius, for which dye decoloriza-tion was not observed. In contrast, the least degraded dye was azorubin, an average of 37% at the end of the experiment for most fungi species. Methylene red showed the most stable decolorization trend, with an average of 77% at the end of the me-asurement. The effect of decolorization was influenced by the structure of the azo dyes and the efficiency of specific fungal species.
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Study on biodegradation of PCBs by white-rot fungi.
Kožená, Lenka ; Bosáková, Zuzana (advisor) ; Olšovská, Jana (referee)
The biodegradation of Delor 103, a commercial mixture of PCB congeners, was studied with eight strains of white rot fungi in two nutritive media: in mineral nitrogen limited medium (so called Kirk medium) and in complex Malt- extract glucose medium. The most efficient biodegradation was observed with the fungus Pleurotus ostreatus, where 99% of PCB congener sum was degraded after 42 days in both media. Bjerkandera adusta was able to degrade 89% of PCB congener sum within 42 days in complex medium. Irpex lacteus removed 70% of PCB congener sum within 42 days in Kirk medium. Other white rot fungi showed lower biodegradation ability, degrading only low chlorinated biphenyls. Further, urgent toxicity of samples was monitored during the Delor 103 biodegradation. P. ostreatus proved to be the most suitable agens for PCB decontamination as a significant reduction of toxicity in comparison with controls was observed during the PCB degradation. In case of other fungi, no reduction of urgent toxicity was observed showing a disadvantage of their use for PCB biodegradation. Activities of ligninolitic enzymes during biodegradation were also studied. In both media laccase activity was detected in Dichomitus squalens, Pycnoporus cinnabarinus and Trametes versicolor cultures. Ligninperoxidase enzyme activity was...
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Využití ligninolytických enzymů v potravinářství
Nadtochaeva, Polina
Ligninolytic enzymes are produced by wood-decaying fungi, and due to their high reactivity and low specificity, they have recently become important enzymes for biotechnological use. This thesis briefly reviews the most important ligninolytic enzymes and their reaction mechanisms and summarizes the ways of using these enzymes in the food industry. Great attention is paid to biosensors, which are used as modern analytical tools for the detection of phenolic compounds. In the experimental part, the own biosensor for the detection and determination of (+) catechin concentration was prepared. The measurement was carried out using a differential pulse voltammetry method using a carbon paste electrode prepared using the immobilized laccase from Trametes versicolor. Measurements of standard solutions have been performed to show that the biosensor can detect even relatively small amounts of catechin. Then the prepared biosensor was used for real samples of red wine and green teas. The content of catechin in four tea samples was measured. The concentrations were approximately the same and ranged from 19.57 to 24.91 mg·l-1. In the case of wine, it has been found that due to the complicated matrix, quantitative analysis is allowed, but requires appropriate mathematical processing of the results or pre-treatment of the samples.
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Bioremediation of persistent aromatic pollutants
Stella, Tatiana ; Cajthaml, Tomáš (advisor) ; Mihaljevič, Martin (referee) ; Tesařová, Eva (referee)
The remediation of persistent chlorinated aromatic compounds has become a priority of great relevance due to the teratogenic, carcinogenic and endocrine-disrupting properties of these xenobiotics. The use of biological methodologies for the clean-up of contaminated sites, collectively referred to as "bioremediation", has been gaining an increasing interest in recent years because it represents an effective, cost-competitive and environmentally friendly alternative to the physico-chemical and thermal treatments. In this respect, "white rot" fungi, an ecological subgroup of filamentous fungi, display features that make them excellent candidates to design an effective remediation technology ("mycoremediation"). In spite of this, fungi have not been widely exploited for their metabolic capabilities and the mechanism by which they are able to degrade the aforementioned pollutants has not been fully elucidated yet. Within this frame, the present Ph.D thesis was aimed at: i) assessing the efficiency of different mycoremediation strategies for the clean-up of a polychlorinated biphenyl (PCBs)-contaminated soil; ii) understanding the fungal degradation pathways of polychlorinated biphenyls and their major metabolites, namely chlorobenzoic acids (CBAs) and hydroxylated polychlorinated biphenyls (OH-PCBs). i)...
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Study on biodegradation of PCBs by white-rot fungi.
Kožená, Lenka ; Olšovská, Jana (referee) ; Bosáková, Zuzana (advisor)
The biodegradation of Delor 103, a commercial mixture of PCB congeners, was studied with eight strains of white rot fungi in two nutritive media: in mineral nitrogen limited medium (so called Kirk medium) and in complex Malt- extract glucose medium. The most efficient biodegradation was observed with the fungus Pleurotus ostreatus, where 99% of PCB congener sum was degraded after 42 days in both media. Bjerkandera adusta was able to degrade 89% of PCB congener sum within 42 days in complex medium. Irpex lacteus removed 70% of PCB congener sum within 42 days in Kirk medium. Other white rot fungi showed lower biodegradation ability, degrading only low chlorinated biphenyls. Further, urgent toxicity of samples was monitored during the Delor 103 biodegradation. P. ostreatus proved to be the most suitable agens for PCB decontamination as a significant reduction of toxicity in comparison with controls was observed during the PCB degradation. In case of other fungi, no reduction of urgent toxicity was observed showing a disadvantage of their use for PCB biodegradation. Activities of ligninolitic enzymes during biodegradation were also studied. In both media laccase activity was detected in Dichomitus squalens, Pycnoporus cinnabarinus and Trametes versicolor cultures. Ligninperoxidase enzyme activity was...
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